Survival trees (random survival forests) generalize trees (random forests) by allowing censored outcomes as inputs and providing covariate-conditional survival probability estimates as outputs. See [1]} and [2]} for survival trees and [3]}, [4]}, and [5]} for random survival forests. Due to censoring, heterogeneity between two nodes cannot be ascertained by a simple mean; alternate tests such as the log-rank test [6]}, [7]}, [8]} must be used. At each terminal node of a survival tree, the survival probability is estimated by the Kaplan-Meier procedure. A random survival forest is obtained by averaging the survival trees.
